Added support for the E-mu Emulator IV bank format (E4B) - not yet tested on hardware

documentation/CHANGELOG.md

@@ -3,7 +3,9 @@
 ## 19.2.0
 
 * New: Added support for a LFO (low frequency oscillator) modulating pitch (vibrato) with its rate, depth and delay: DecentSampler, DLS, SFZ, SoundFont 2. Previously any vibrato was dropped on conversion.
-
+* New: Added support for the E-mu Emulator IV bank format (E4B). The name of the bank is passed on as the description and - switchable - prepended to the name of a read preset, since the presets of the EOS libraries are only named after their articulation ('Dark Tremolo') and not after the instrument they play. Written banks have not been tested on real hardware yet.
+* New: E-mu Emulator IV banks can also be read directly from CD-ROM and hard disk images of the EOS samplers (ISO, IMG, HDA), including via the ISO/IMG source format.
+* New: The E-mu Emulator IV destination can write the bank as a ready-to-use CD-ROM image for SCSI CD-ROM emulators (e.g. ZuluSCSI), which is the only way to load banks on units running EOS versions before 4.7.
 * Kurzweil K2x00
   * Fixed: An envelope stage with both a zero time and a zero level is unused on the device and keeps the level of the previous stage, but was read literally. A program which leaves its decay stage unused - like the reported FM basses, which sustain at the attack level and only fade out with a long release - was therefore converted to a silent preset. Additionally, the attack velocity is now converted as a cutoff modulation source of the F1 slot in both directions; the same programs open their nearly closed cutoff by velocity and converted very dull without it.
 

documentation/README-FORMATS.md

@@ -278,6 +278,29 @@ The DLS format (*.dls) is a standardized file format developed for storing and d
 There is no write support.
 
 The amplitude and pitch envelopes, the sample loops and a pitch LFO (vibrato) are read. The vibrato's depth, its frequency (converted from absolute pitch cents to Hertz) and its start delay are carried over to the pitch LFO. Only a connection which is not modulated by a controller is read as the vibrato; the format normally contains a second one controlled by the modulation wheel, which is the amount the wheel can dial in and would sound permanently if it were converted.
+## E-mu Emulator IV
+
+The E-mu Emulator IV series (Emulator 4, E4X, E4XT, E4K, e-Synth, e-6400 and the other EOS samplers, 1994-2002) stores its banks in single *.e4b* files which contain all presets, their parameters and the sample data. A preset layers several voices; each voice maps a set of zones (a key/velocity range referencing a sample) and carries the tuning, volume, filter, envelope and modulation settings for them. The format is not documented by E-mu, the layout was reverse-engineered by the mpc2emu project from hardware-saved E4XT banks and commercial EOS CD-ROMs (see *documentation/design/E4B_FORMAT.md*).
+
+Banks can be read from single *.e4b* files and also directly from CD-ROM and hard disk images of the EOS samplers (*.iso*, *.img*, *.hda* - e.g. images for SCSI emulators like the ZuluSCSI or dumps of commercial E-mu CD-ROMs), which use the proprietary E-mu disk filesystem. All banks of an image are read; files of the older EIII samplers, which use the same filesystem for their banks, are skipped.
+
+When reading, every preset of a bank becomes one multi-sample and every voice becomes a group. Names, key and velocity ranges, root keys, tuning, volume, panning, loops, the amplitude envelope with its velocity modulation, the filter (type, cutoff, resonance, key tracking and envelope with its depth) and the 16-bit sample data are read. The per-zone offsets for fine tuning, volume and panning are applied on top of the settings of their voice, and the pitch offset of a sample is applied as a fine tuning as far as it detunes the sample beyond compensating its sample rate. The EOS effect filter types (phasers, flangers, vocal formants, EQ morphs) have no model equivalent, such voices are converted without a filter.
+
+The name of the bank is passed on as the description of the multi-sample, which the formats that have a field of their own for the bank take it from - the Waldorf Quantum/Iridium for example shows it next to the preset name.
+
+The presets of the commercial EOS libraries are named after the articulation or the variation they provide (*Dark Tremolo*, *Long Release*, ...) while the instrument they actually play is only given by the name of their bank. The name of the bank is therefore prepended to the name of the preset as well, except when the preset name already starts with it - the *Dark Tremolo* preset of the *Greek Bazouki* bank becomes *Greek Bazouki - Dark Tremolo* while *Greek Bazouki XS* is kept unchanged. This also keeps the presets of different banks apart, which would otherwise overwrite each other since a name like *Natural Range* is used in many banks. If the folder structure of the source is created, each bank additionally gets a folder of its own.
+
+A written bank does not repeat this in its preset names, since the file itself is that bank and its preset names hold only 16 characters - which the bank alone would fill. The file name of the bank keeps the full name.
+
+#### Source Options
+
+* Prepend the bank name to the preset name: Enabled by default, see above. Disable it to keep the preset names exactly as they are in the bank - the bank is then only carried in the description, and the written file names are the bare preset names.
+
+When writing, each multi-sample becomes one preset; a library collects all multi-samples into a single bank (up to 1000 presets and 1000 samples). Every zone is written as its own voice, which keeps all per-zone settings; the panning, which only exists per zone, is written into the zone entry. Samples are stored as 16-bit mono PCM with their original sample rate (rates above 48kHz, the EOS maximum, are down-sampled); stereo samples are mixed down to mono. Identical samples mapped to multiple zones are stored only once. Since EOS only has a sample-level forward loop, alternating loops are written as forward loops and only the first loop of a zone is kept. Written banks validate against the reference parser of the mpc2emu project but have not been verified on real hardware yet.
+
+#### Destination Options
+
+* Create CD-ROM image (.iso) for SCSI CD-ROM emulators: The bank is wrapped into a CD-ROM image (*.iso*) with the proprietary E-mu disk filesystem. Copy the image to the SD card of a SCSI emulator (e.g. rename it to *CD1.iso* for a ZuluSCSI in CD-ROM mode) and load the bank on the sampler from the emulated CD-ROM drive. This works on all EOS versions and on units which cannot read FAT hard disks (EOS before 4.7); a plain bank file instead requires a FAT formatted hard disk and EOS 4.7 or later.
 
 ## Elektron Tonverk
 
@@ -369,9 +392,10 @@ Note that this will not work with IIx or earlier versions despite the same VC fi
 
 ## ISO/IMG Files
 
-Searches for files ending with *.ISO or *.IMG. Currently, the following formats can be handled:
+Searches for files ending with *.ISO, *.IMG or *.HDA. Currently, the following formats can be handled:
 
 * [Akai S1000/3000](#akai-s1000s3000-series-disk-image)
+* [E-mu Emulator IV](#e-mu-emulator-iv)
 * [Akai MPC2000/MPC2000XL](#akai-mpc2000mpc2000xlmpc3000)
 * [Ensoniq EPS/ASR](#ensoniq-epseps16asr-10) (only *.ISO)
 * [Roland S-50 series](#roland-s-50-series)